Should I keep a local copy of my website in case of trouble?
Absolutely! It is very easy to spend all night working hard on upgrading your site only to hit the wrong key or have someone else overwrite your changes. Better safe than sorry.
You may also easily backup your files, databases, email forwarders (aliases), and email filters in Cpanel under Backup. We highly recommend doing so.You can use backup wizard inside of your cPanel account.